[PowerPC] Fix missing GOT indirect variant kind

[stefanp]

Summary

The function MCSymbolRefExpr::getVariantKindForName was missing the entry for VK_PPC_GOT_PCREL.
This patch adds the missing entry.

[kamaub]

This LGTM, one minor comment about test case explanation, it can be done pre-commit for sure.

llvm/test/MC/PowerPC/future-reloc.s

6

Could you add a brief explanation of this test case here

llvm/lib/MC/MCExpr.cpp

return StringSwitch<VariantKind>(Name.lower())
     .Case("got@tlsgd", VK_PPC_GOT_TLSGD)
     .Case("got@tlsgd@l", VK_PPC_GOT_TLSGD_LO)
     .Case("got@tlsgd@h", VK_PPC_GOT_TLSGD_HI)
     .Case("got@tlsgd@ha", VK_PPC_GOT_TLSGD_HA)
     .Case("got@tlsld", VK_PPC_GOT_TLSLD)
     .Case("got@tlsld@l", VK_PPC_GOT_TLSLD_LO)
     .Case("got@tlsld@h", VK_PPC_GOT_TLSLD_HI)
     .Case("got@tlsld@ha", VK_PPC_GOT_TLSLD_HA)
+    .Case("got@pcrel", VK_PPC_GOT_PCREL)
     .Case("notoc", VK_PPC_NOTOC)
     .Case("gdgot", VK_Hexagon_GD_GOT)
     .Case("gdplt", VK_Hexagon_GD_PLT)
     .Case("iegot", VK_Hexagon_IE_GOT)
     .Case("ie", VK_Hexagon_IE)
     .Case("ldgot", VK_Hexagon_LD_GOT)
     .Case("ldplt", VK_Hexagon_LD_PLT)
     .Case("none", VK_ARM_NONE)

llvm/test/MC/PowerPC/future-reloc.s

+# RUN: llvm-mc -triple=powerpc64le-unknown-unknown -filetype=obj %s 2>&1 | \
+# RUN: FileCheck %s -check-prefix=MC
+# RUN: llvm-mc -triple=powerpc64le-unknown-unknown -filetype=obj %s | \
+# RUN: llvm-readobj -r | FileCheck %s -check-prefix=READOBJ
+
+# This test checks that on Power PC we can correctly convert @pcrel and
+# @got@pcrel into R_PPC64_PCREL34 and R_PPC64_GOT_PCREL34.
+
+# MC-NOT:    error: invalid variant
+
+# READOBJ:        0x0 R_PPC64_PCREL34 locvalue 0x0
+# READOBJ-NEXT:   0x20 R_PPC64_GOT_PCREL34 evalue 0x0
+
+  .text
+  .abiversion 2
+  .globl  local                   # -- Begin function local
+  .p2align  4
+  .type local,@function
+local:                                  # @local
+.Llocal$local:
+.Lfunc_begin0:
+# %bb.0:                                # %entry
+  plwa 3, locvalue@PCREL(0), 1
+  blr
+  .long 0
+  .quad 0
+.Lfunc_end0:
+  .size local, .Lfunc_end0-.Lfunc_begin0
+                                        # -- End function
+  .globl  external                # -- Begin function external
+  .p2align  4
+  .type external,@function
+external:                               # @external
+.Lexternal$local:
+.Lfunc_begin1:
+# %bb.0:                                # %entry
+  pld 3, evalue@got@pcrel(0), 1
+  lwa 3, 0(3)
+  blr
+  .long 0
+  .quad 0
+.Lfunc_end1:
+  .size external, .Lfunc_end1-.Lfunc_begin1
+                                        # -- End function
+  .type locvalue,@object        # @locvalue
+  .section  .bss,"aw",@nobits
+  .globl  locvalue
+  .p2align  2
+locvalue:
+.Llocvalue$local:
+  .long 0                       # 0x0
+  .size locvalue, 4
+